Network computer systems generally include a plurality of geographically separated or distributed computer nodes that are configured to communicate with each other via, and are interconnected by, one or more network communications media. One conventional type of network computer system includes a network data storage subsystem that is configured to provide a centralized location in the network at which to store, and from which to retrieve data. Advantageously, by using such a storage subsystem in the network, many of the network's data storage management and control functions may be centralized at the subsystem, instead of being distributed among the network nodes.
One type of conventional network data storage subsystem, manufactured and sold by the Assignee of the subject application (hereinafter “Assignee”) under the tradename Symmetrix™ (hereinafter “the Assignee's conventional storage system”), includes a plurality of disk mass storage devices configured as one or more redundant arrays of independent (or inexpensive) disks (RAID). The disk devices are controlled by disk I/O controllers (commonly referred to as “back end” directors) that are coupled to a shared cache memory resource in the subsystem. The cache memory resource is also coupled to a plurality of host I/O controllers (commonly referred to as “front end” directors). The disk controllers are associated with and coupled to respective disk adapters that, among other things, interface the disk controllers to bus systems (e.g., small computer system interface (SCSI) based bus systems) used to couple the disk devices to the disk controllers. Similarly, the host controllers are associated with and coupled to respective host channel/network adapters that, among other things, interface the host controllers via channel input/output (I/O) ports to the network communications channels (e.g., Gigabit Ethernet, SCSI, Enterprise Systems Connection (ESCON), or Fibre Channel (FC) based communications channels) that couple the storage subsystem to computer nodes in the computer network external to the subsystem (commonly termed “host” computer nodes or “hosts”). Each respective host controller may control and monitor the operations of the respective network adapter to which the respective host controller is coupled. In order to facilitate this, each respective network adapter includes a respective control interface via which the respective network adapter's associated host controller may issue commands to the respective network adapter, and from which the controller may receive information from the adapter concerning the operational status of the adapter.
The Assignee's conventional storage system may include a plurality of differently configured network adapters that may facilitate communication among respective host controllers and respective sets of host nodes using respective subsets of communication channels. For example, if the data storage network comprises FC communication channels, the Assignee's conventional storage system may include at least a first type of network adapter and a second, different type of network adapter. The first type of network adapter may have a hardware and/or software/firmware configuration that may permit the first type of adapter to facilitate communication among its associated host controller and a set of associated host nodes, via a first predetermined number of FC communication channels. The second type of network adapter may have a different hardware and/or software configuration (i.e., different from that of the first type of network adapter) that may permit the second type of adapter to facilitate communication among its associated host controller and a different set of associated host nodes via a second predetermined number of FC communication channels that may be different from the first predetermined number.
In the Assignee's conventional storage system, the control interfaces that are used in mutually dissimilar types of network adapters typically also are mutually dissimilar. Unfortunately, this has meant that unless a host controller has been specifically designed to use the particular control interface in a specific type of network adapter, that controller may be incompatible with (i.e., be unable to use) that control interface. Disadvantageously, this inherently limits the ability of respective host controllers to control and monitor the operation of different types of network adapters, and increases the amount of design effort required to ensure host controller-network adapter compatibility. It would be desirable to increase the ability of respective host controllers to control and monitor different types of network adapters, and decrease the amount of design effort required to ensure host controller-network adapter compatibility, by providing in the different types of network adapters respective “standardized” control interfaces (i.e., control interfaces that have identical respective constructions and operations).